SDR DALA2015042002813

Service difficulty report · Control Valve · Boeing 757232

Difficulty date: April 17, 2015
Submitted: April 20, 2015
Operation: Air carrier
Aircraft: N663DN
Make and model: Boeing 757232
Aircraft serial: 24992
Aircraft time: 78,363 hours, 35,821 cycles
Engine: Pwa PW2037
Engine time: 38,624 hours, 13,791 cycles
System (JASC): 2150 · Cabin Cooling System
Part: Control Valve
Condition: Failed
Location: Rt A/C Pack
Stage of operation: CR
How discovered: O
Nature of condition: O
Precautionary procedure: A

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

DESCENDING OUT OF FL330 TO FL270 CABIN ALTITUDE LIGHT ILLUMINATED, CONTINUED DESCENT TO 10000, CABIN ALTITUDE REACH 10,500. CABIN ALTITUDE DROPPED BELOW 10,000 AS DESCENT CONTINUED THROUGH 20,000. CABIN STABILIZED AT 8500 FEET WHEN ACFT WAS AT 10,000 FEET. PASSENGER MASKS DIDN'T NOT DROP. CREW DONNED OXYGEN MASKS AND DECLARED AN EMERGENCY. MAINTENANCE REPLACED, RT PACK FCV, LT BLEED REPLACED HPSOV AND CONTROLLER MAINTENANCE IN PROGRESS.